Piano



FIG. 1 is a front view of a piano showing my new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a right-side view thereof;

FIG. 4 is a top view thereof; and,

FIG. 5 is a bottom view thereof.

The details shown in broken lines in all the views are for illustrative purposes only and form no part of the claimed design. 

I claim the ornamental design for a piano, as shown and described. 